Effect of poly(vinyl pyrrolidone ) on the morph ology and physical properties of poly(vinyl alcohol) /sodium montmorill onite nanocompos ite films

Nanocomposites of poly(vinyl alcohol)(PVA),poly(vinyl pyrrolidone)(PVP) and sodium montmorillonite(Na~+MMT) were prepared by solution mixing and then cast into films.X-ray diffraction analysis and images of transmission electron microscopy establish the formation of PVA/Na~+MMT intercalated nanocomposite.Exfoliated and highly intercalated PVA/PVP/Na~+MMT nanocomposite formed in the presence of PVP.Inclusion of PVP in PVA/Na~+MMT matrix enhances the hydrogen bonding interactions between PVA and Na~+MMT and thus increases the mechanical properties and thermal stability of PVA/PVP/Na~+MMT nanocomposites compared to PVA/Na~+MMT nanocomposite.The interactions between PVA,PVP and Na~+MMT were established by the Fourier transform infrared spectroscopy.The moisture absorption tendency of both the PVA and PVA/PVP films reduced after the incorporation of Na~+MMT at 75%constant relative humidity.Differential scanning calorimetry studies show that the presence of PVP and Na~+MMT both are responsible for reducing the heat of fusion,and crystallinity of PVA.The flow behavior of the PVA,PVA/PVP and its nanocomposite solutions has been also studied.Water vapor permeability of PVA/PVP/Na~+MMT composite films decreased in the presence of nanoclay due to increasing tortuous paths for diffusion.     

聚氯乙烯／三元共聚尼龙共混物的形态结构

采用乙烯-丙烯酸正丁酯-一氧化碳共聚物（EnABCO）及马来酸酐接枝乙烯-丙烯酸正丁酯-一氧化碳共聚物（EnABCO-g-MAH)两种增容剂对聚氯乙烯（PVC）/三元共聚尼龙（NT）共混物进行增容,得到了一类新型的PVC/NT共混物,用SEM,DMTA、DSC对共混物的形态结构,结晶情况进行了表征;对增容剂的增容机理和增容效果进行了探索与评价;结果表明：增容和未增容PVC/NT共混物都是典型的的两相体系;PVC/NT质量比在75/25～25/75的范围内NT均为连续相;共混物中EnABCO比EnABCO-g-MAH对PVC有更强的增塑作用,共混物有冷结晶现象,EnABCO增容共混物中的NT结晶能力比较弱。     

EVA增容PVC／SBS共混体系的研究

本文通过冲击实验，拉伸实验，动态力学分析及扫描电镜的观察，研究了ＥＶＡ增容的ＰＶＣ／ＳＢＳ共混体系的形态结构的关系。研究结果表明，ＥＶＡ对ＰＶＣ／ＳＢＳ有良好的增容作用，并且与ＳＢＳ一起对ＰＶＣ有协同增韧效果。     

Synthesis of PCL/MWCNT by One-Pot with Microwave-Assistant and Its Mechanical Properties

Polycaprolactone/multi-walled carbon nanotubes nano composite (PCL/MWCNT) was synthesized by a one-pot process with microwave-assistance. The fractured structures, crystalline behaviors and thermal properties of the nanocomposites were investigated with an electronic microscope, an X-ray diffraction device, an infrared spectroscopy, and a differential scanning calorimeter, respectively. A universal testing machine was used to study the mechanical properties of the composites. The results showed that when the content of MWCNT was 0.3 % (m/m), the tensile strength and elongation at break reached the maximum values, and increased from 7.5 MPa and 125 % of neat PCL to 14.8 MPa and 387 %, respectively. With an increase of the MWCNT content, the Young’s modulus continuously increased from 121.5 MPa of PCL to 285.6 MPa. When the MWCNT content was 0.5 % (m/m), the Young’s modulus was ca. 1.4 fold over that of neat PCL, indicating that the addition of MWCNT resulted in simultaneous enhancement of strength, toughness and modulus remarkably.     

PVC／NBR／SBS三元共混物的形态结构与性能

本文通过冲击试验、动态力学分析（ＭＭＡ）、透射电镜（ＴＥＭ）和扫描电镜（ＳＥＭ）观察，研究了聚氯乙烯／丁腈橡胶／苯乙烯。丁二烯。苯乙烯嵌段共聚物（ＰＶＣ／ＮＢＲ／ＳＢＳ）三元共混物的形态结构和性能，并且讨论了两者之间的关系。ＮＢＲ－２９对ＰＶＣ和ＳＢＳ有较好的增容作用，与ＳＢＳ一起对ＰＶＣ有协同增韧效应。     

Biodegradable starch/poly (vinyl alcohol) film reinforced with titanium dioxide nanoparticles

Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-TiO₂) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO₂ nanocomposites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of TiO₂ nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO₂ films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films.     

Influences of poly (vinyl alcohol) molecular weight and carbon nanotubes on radiation crosslinking shape memory polymers

Polyvinyl alcohol (PVA) of two molecular weights was used to prepare shape memory polymers based on chemical-crosslinking by glutaraldehyde. The chemical-crosslinking was done in the presence of 2-carboxyethyl acrylate oligomers (CEA) and nano-filler [multi-wall carbon nanotubes (MWCNT) and functionalized carbon nanotubes (MWCNT-NH2)] followed by radiation-induced crosslinking. The analysis of the material revealed an increase in the gel fraction and a significant reduction in swelling of the nanocomposite material that was crosslinked with both glutaraldehyde and ionizing radiation. The radiation crosslinked nanocomposites demonstrated approximately a 90% gelation over a range of 50–300 kGy irradiation doses. The scanning electron microscopy (SEM) analysis showed a homogeneous distribution of nanocomposites in the composite matrix. The thermal properties of radiation crosslinked (PVA/CEA) and (PVA-CEA)-nano-fillers were investigated by a thermogravimetric analysis (TGA). The mechanical properties were examined via dynamic mechanical analysis (DMA) which showed significant variation because of the addition of nanocomposites. This radiation crosslinked materials show good shape memory behavior that may be useful in many applications based on the range of temperatures at which Tan δ appears.     

高透明紫外阻隔聚碳酸酯/ZnO纳米复合高分子膜的制备与表征

采用溶液共混法将纳米ZnO颗粒添加到聚碳酸酯（PC）中,制备得到了具有高透明性、高紫外线屏蔽能力的PC/ZnO纳米复合高分子膜。分别使用傅立叶转换红外线光谱（FT-IR）、扫描电子显微镜（SEM）、紫外-可见分光光度计对纳米复合膜的光学性能进行了分析和表征。结果表明当纳米ZnO的添加量为10%（质量分数）时,复合膜的可见光透过率为98%,与未添加纳米ZnO的PC膜一致。与市售隔紫外线PC产品对比,纳米复合膜同时具有较好的透明度和紫外线屏蔽能力,紫外线的阻隔率可达92%。     

PVC/CPE/P(BA-co-MMA)改性CaCO_3复合体系的性能研究

基于CPE和P(BA-co-MMA) 改性CaCO3对PVC的协同增韧效应,用其填充PVC,研究加工工艺、CPE及改性CaCO3用量对复合材料力学、流变和热性能的影响.结果显示,二次分散法利于发挥弹性体与刚性无机粒子的协同效应;当m(PVC)∶m(CPE)∶m(改性CaCO3) =100∶8∶10时,PVC/CPE/改性CaCO3复合体系的冲击强度可达15.24 kJ/m2,为纯PVC基体树脂的3.98倍;随着CaCO3用量的增加,体系在保持加工流动性的同时耐热性能逐步改善;ESEM分析表明,复合材料的冲击断面呈现出典型的韧性破坏特征.     

Self-assembly of mesoscopically ordered chromatic polydiacetylene/silica nanocomposites

Nature abounds with intricate composite architectures composed of hard and soft materials synergistically intertwined to provide both useful functionality and mechanical integrity. Recent synthetic efforts to mimic such natural designs have focused on nanocomposites, prepared mainly by slow procedures like monomer or polymer infiltration of inorganic nanostructures or sequential deposition. Here we report the self-assembly of conjugated polymer/silica nanocomposite films with hexagonal, cubic or lamellar mesoscopic order using polymerizable amphiphilic diacetylene molecules as both structure-directing agents and monomers. The self-assembly procedure is rapid and incorporates the organic monomers uniformly within a highly ordered, inorganic environment. Polymerization results in polydiacetylene/silica nanocomposites that are optically transparent and mechanically robust. Compared to ordered diacetylene-containing films prepared as Langmuir monolayers or by Langmuir-Blodgett deposition, the nanostructured inorganic host alters the diacetylene polymerization behaviour, and the resulting nanocomposite exhibits unusual chromatic changes in response to thermal, mechanical and chemical stimuli. The inorganic framework serves to protect, stabilize, and orient the polymer, and to mediate its function. The nanocomposite architecture also provides sufficient mechanical integrity to enable integration into devices and microsystems.     

Electrodeposition of functionally graded Ni-W/Er_2O_3 rare earth nanoparticle composite film

Multi-layered functionally graded(FG) structure Ni-W/Er_2O_3 nanocomposite films were prepared by continuously changing the deposition parameters, in which the Er_2O_3 and W contents varied with thickness. The microstructure and chemical composition of the electrodeposited Ni-W/Er_2O_3 films were determined by scanning electron microscopy(SEM) and energy-dispersive X-ray spectroscopy(EDS). The anti-corrosion and wear properties of the electrodeposition films were investigated by electrochemical measurement and ball-on-disk friction test. The microhardness distribution of the cross section of nanocomposites was measured by nanoindentation. The results showed that with decreasing agitation rate or increasing average current density, the contents of Er_2O_3 nanoparticles and tungsten were distributed in a gradient along the thickness, and the contents on the surface were larger. By comparison, FG Ni-W/Er_2O_3 films had better anti-corrosion and wear properties than the uniform Ni-W/Er_2O_3 films. Atomic force microscopy(AFM) and profilometry measurements indicated that Er_2O_3 nanoparticles had an effect on the surface roughness.     

改性石墨烯/聚氨酯复合乳液的合成及性能表征

通过逐步聚合反应将改性氧化石墨烯(DIGN)接枝到水性聚氨酯(WPU)链段中,制备得到DIGN/WPU纳米复合乳液。通过IR、AFM、SEM对氧化石墨烯(GO)、DIGN、WPU及DIGN/WPU纳米复合材料的结构进行表征;并研究了DIGN用量对乳液粒径,流变性能及其胶膜的热稳定性和力学性能的影响。结果表明:DIGN的引入使得乳液具有了假塑性流体特性,并随DIGN含量的增加,乳液黏度,粒径及分布指数增大,纳米复合材料的热稳定性明显改善;当w(DIGN)=1wt%时,拉伸强度增加80.33%,杨氏模量提高192.11%,断裂伸长率下降了42.74%。     

Effect of CNTs and nano ZnO on physical and mechanical properties of polyaniline composites applicable in energy devices

Polyaniline was synthesized chemically in an acidic medium in the presence of Ammonium Peroxydisulphate (APS) as an oxidizing agent. PANI(Polyaniline) nanocomposites were prepared in the presence of various amount of carbon nanotube and zinc oxide (from 1 to 5 wt%) by solution casting method. The free-standing film of polyaniline and its nanocomposites were obtained by vaporization of solvent content. The composition, morphology and structure of the polymer and the nanocomposites were characterized by Fourier transform infrared spectroscopy FT-IR spectra, scanning electron microscopy (SEM) image and XRD pattern. In addition, thermal stability was studied by TGA analysis, electrical conductivity was measured by four-point probe technique and mechanical properties were studied by tensile strength test. The characteristic FTIR peaks of PANI were found to shift to lower wave number in nanocomposites due to the formation of H-bonding. XRD results revealed that the crystallinity of PANI was more noticeable after addition of nano-ZnO, while the intensity of the peaks increased by the addition of ZnO nanoparticles. Furthermore, TGA results showed that the decomposition of the nanocomposite was less than that of pure polyaniline which confirms the successful fabrication of products. Young''s modulus and strength at break point were increased in the case of the nanocomposite, in addition, the electrical conductivity of the PANI/ZnO nanocomposite film was found to be smaller than that of the PANI film while CNTs increase the conductivity of polyaniline.     

新型PVC色母料的应用性能

采用热分析系统、扫描电镜、热流变仪及力学性能测试方法,研究了新型ＰＶＣ色母料在ＰＶＣ塑料中的分散性及该母料对ＰＶＣ塑料力学性能、热稳定性和流动性的影响。结果表明,该ＰＶＣ色母料热稳定性好,用其对ＰＶＣ塑料进行着色,着色均匀,色彩鲜艳,且不影响ＰＶＣ制品的机械性能,是一种较理想的ＰＶＣ塑料着色方法。     

界面氢键结合的天然橡胶/改性气相法白炭黑纳米复合材料

用间苯二酚与六亚甲基四胺络合物（RH）对气相法白炭黑进行表面改性,通过混炼和硫化制备了天然橡胶/改性气相法白炭黑（NR/M-silica）纳米复合材料,并通过力学性能测试、交联密度测定、透射电镜、差示扫描量热法、红外光谱和X射线光电子能谱等手段研究了纳米复合材料的结构和性能．结果表明：M-silica对NR硫化胶的补强效果显著优于未改性的气相法白炭黑,当M－silica用量为4～10份时,硫化胶的力学性能最佳;M-silica在橡胶基体中分散良好,硫化胶的交联密度和玻璃化温度提高;在改性剂RH作用下,白炭黑的Si-O键和硅羟基的红外光谱特征吸收峰发生明显的蓝移,且O原子的结合能发生明显的变化,表明白炭黑表面的硅羟基与RH受热后形成的间苯二酚甲醛树脂中的酚羟基之间形成了明显的氢键作用．在上述研究的基础上讨论了RH改性气相法白炭黑补强天然橡胶的机理．     

聚氯乙烯/蒙脱土纳米复合材料的结构与力学性能

选用钠基蒙脱土和2种烷基季铵盐(十八烷基季铵盐和双十八烷基季铵盐)改性的蒙脱土，采用熔融共混的方法制备聚氯乙烯／蒙脱土纳米复合材料，并通过广角X射线衍射和透射电镜对复合材料的结构进行了表征．研究了蒙脱土种类和用量对复合材料力学性能的影响．结果表明，3种复合材料均具有插层型结构，钠基蒙脱土用量在ω＝0．5％-7．0％，有机蒙脱土用量在20＝0．5％-3．0％时，复合材料的综合力学性能均有明显提高；有机蒙脱土用量ω＞5．0％以后，材料的力学性能降低，热稳定性变差．     

Influence of Dispersion of Nano-ZnO Particles in Polymer Matrices on Properties of Relevant Nano Composite Fibers

IntroductionIt is well knownthat nanoparticles have rich propertiesand are useful for functional composites . The nanometricsize ,leading to huge specific surface area up to or morethan1 000m2/g ,andtheir unique properties have attractedintensive interests . Thus many articles have elucidated thepreparation of polymer matrix nanocomposites( PMNC)[1 6]. Polymers are very i mportant matricesbecause of their flexibility and easy processing .Nanoparticles i mpart larger-size congeries because of…     

Antifungal activity of magnetically separable Fe3O4/ZnO/AgBr nanocomposites prepared by a facile microwave-assisted method

In the present work, magnetically separable Fe-₃O₄/ZnO/AgBr nanocomposites with different weight ratios of Fe₃O₄ to ZnO/AgBr were prepared by a facile microwave-assisted method. The resultant samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive analysis of X-rays（EDX）, and vibrating sample magnetometery（VSM）. Antifungal activity of the as-prepared samples was evaluated against Fusarium graminearum and Fusarium oxysporum as two phytopathogenic fungi. Among the nanocomposites, the sample with 1:8 weight ratio of Fe₃O₄ to ZnO/AgBr was selected as the best nanocomposite. This nanocomposite inactivates Fusarium graminearum and Fusarium oxysporum at 120 and 60 min, respectively. Moreover, it was observed that the microwave irradiation time has considerable influence on the antifungal activity and the sample prepared by irradiation for 10 min showed the best activity. Moreover, the nanocomposite without any thermal treatment displayed the superior activity.     

金属配合物在阻燃软聚氯乙烯(PVC)中的应用

研究了金属配合物与（Al（OH）3和Mg（OH）2）复合阻燃剂对软聚氯乙烯（PVC）的阻燃消烟作用。用Kissinger方程求出了聚合物降解反应的活化能，用热分析的方法结合氧指数、烟密度及剩炭率的测定，同时结合电子扫描显微镜（SEM）对剩炭结构的观察研究了金属配合物与氢氧化物（MH）对软PVC的阻燃机理及协同作用．对阻燃处理后的样品的机械性能进行了测定．结果表明：金属配合物与氢氧化物在配比合适时存在明显的协同作用，对软PVC有较好的阻燃消烟效果，这是由于金属配合物的催化成炭与氢氧化物对烟粒的吸附共同作用的结果．同时由于阻燃剂的添加量较小，对样品的力学性能影响不大．     

溶胶-凝胶法制备PVC/SiO_2杂化材料及其性能研究

通过甲基丙烯酰氧丙基三甲氧基硅烷同正硅酸乙酯共水解,在ＳｉＯ２ 表面引入能与ＰＶＣ相容的极性基团,制备了ＰＶＣ／ＳｉＯ２ 杂化材料的透明薄膜．讨论了溶剂对材料、结构的影响,通过红外分析,透射电镜研究了杂化材料的形态和通过动态力学分析,力学性能分析研究了无机组份对材料性能的影响